Volume 11, the sixth of the historical volumes of A Treatise of Legal Philosophy and General Jurisprudence, offers a fresh, philosophically engaged, critical interpretation of the main currents of jurisprudential thought in the English-speaking world of the 20th century. It tells the tale of two lectures and their legacies: Oliver Wendell Holmes, Jr.'s "The Path of Law" (1897) and H.L.A. Hart's Holmes Lecture, "Positivism and the Separation of Law and Morals" (1958). Holmes's radical challenge to late 19th century legal science gave birth to a rich variety of competing approaches to...